Electric Propulsion System Configuration and Control of Vessels by Using Multilevel Inverters

Reducing total harmonic distortion (THD) in propulsion drive systems is essential. By reducing the THD, the output filter of the inverter can be removed, or its volume can be reduced. This paper proposes a multilevel inverter (MLI) for floating electric propulsion systems. This inverter uses asymmetric DC sources, increasing the output voltage levels. Comparing this inverter with other inverters shows that this inverter can produce more voltage levels at the output with fewer switches. This comparison is given in this article. To confirm the closed-loop operation of the drive system, a simulation was done using MATLAB Simulink software. Two different controllers (proportional-integral (PI) and sliding mode controller (SMC) are used in the simulation. The performance of these two controllers is also compared.